Key parameters at a glance

A radius of 1.66 Earth radii
A mass of 3.41 Earth masses
Surface gravity around 1.24 g
An orbital period of 17.872 days
Semi-major axis 0.0890 AU
Distance from Earth 14.04 light-years
Earth Similarity Index 0.855
Travel time at Voyager 1 speed 247,666 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

Wolf 1061 c is an exoplanet orbiting within the habitable zone of the red dwarf star Wolf 1061 in the constellation Ophiuchus, about 14.1 light-years from Earth. At the time of discovery, it was the closest known potentially habitable exoplanet to Earth, though several closer ones have since been found. It is the second planet in order from its host star in a triple planetary system, and has an orbital period of 17.9 days. Wolf 1061 c is classified as a super-Earth exoplanet as its mass is between that of Earth and the ice giants.

Excerpted from Wikipedia · full article

2 siblings around Wolf 1061

Wolf 1061 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Wolf 1061 b	Rocky Terrestrial	1.21	1.91	4.887	—	2015
Wolf 1061 c this	Super-Earth	1.66	3.41	17.872	—	2015
Wolf 1061 d	Sub-Neptune	2.69	7.70	217.210	—	2015

Wolf 1061 c Planet Profile

Physical Specs

Radius

1.66 R⊕

Radius (Jupiter)

0.148 R♃

Mass

3.41 M⊕

Mass (Jupiter)

0.011 M♃

Density

4.10 g/cm³

Surface Gravity

1.24 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.855

HZ Position Habitable

Controversial No

Discovery

Year 2015

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#469of 1176

top 39.8%

This planet

1.66R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-379 b 1.66 R⊕ Kepler-1497 b 1.66 R⊕ GJ 357 c 1.66 R⊕

Metric	Earth	Wolf 1061 c	Jupiter
Radius (R⊕)	1.00	1.66	11.21
Mass (M⊕)	1.00	3.41	317.83
Density (g/cm³)	5.51	4.10	1.33
Surface Gravity (g)	1.00	1.24	2.53
Insolation (S⊕)	1.00	1.30	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	3.410 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 80824

TIC

TIC 413948621

Gaia DR2

Gaia DR2 4330690742322011520

Gaia DR3

Gaia DR3 4330690742322011520

System

Wolf 1061

Percentile among Super-Earth cohort

Radius 1.660 R⊕ · percentile 59 / cohort 1176

Mass 3.410 M⊕ · percentile 55 / cohort 1176

Orbital period 17.87 d · percentile 82 / cohort 1164

Distance 4.31 pc · percentile 0 / cohort 1171

ESI 0.855 · percentile 94 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

17.872 days

Semi-major axis

0.0890 AU

Eccentricity

0.110

Inclination

— °

Year Length

A year here lasts approximately 17.87 Earth days (4.9% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0890 AU.

Eq. Temperature

—

Insolation (S⊕)

1.30

Earth = 1.00

Earth Similarity (ESI)

0.855

0 = alien, 1 = Earth-identical

Within the conservative habitable zone. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Wright et al. 2016

Instrument

HARPS Spectrograph

Publication

2016-02

Observation locale

Ground

Discovery cohort

Planets confirmed in 2015 at La Silla Observatory (10 shown).

Wolf 1061 b · Rocky Terrestrial HD 1461 c · Sub-Neptune GJ 3341 b · Sub-Neptune Wolf 1061 d · Sub-Neptune HD 204313 c · Neptune-like GJ 3293 c · Neptune-like GJ 3293 b · Neptune-like WASP-41 c · Gas Giant HD 175607 b · Unclassified WASP-47 c · Unclassified

Host System: Wolf 1061

Spectral Class

M-type red dwarf

Effective Temperature

3,342 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.307 R☉

Stellar Mass

0.294 M☉

Metallicity [Fe/H]

-0.09

Extended Stellar Properties

Surface gravity (log g)

4.902 dex

Stellar density

12.748 g/cm³

Systemic radial velocity

-21.04 km/s

Rotation period

95.00 days

Metallicity ratio

[Fe/H]

Distance

4.31 parsec

Light-years 14.04 ly

V-band magnitude

10.10 mag

Voyager-speed travel 247,666 yr

Multi-band Host Photometry — 8 bands

Astrometric Data

Parallax

232.210 mas

Total Proper Motion

1,187.508 mas/yr

PM Right Ascension

-94.03 mas/yr

PM Declination

-1,183.78 mas/yr

Galactic Cartesian (pc)

x = -0.372 · y = -0.902 · z = -0.219

Equatorial (J2000)

RA 247.57483° · Dec -12.66769°

Galactic ℓ, b

3.347° · 23.677°

Ecliptic λ, β

247.854° · 9.064°

HTM-20 index

922353005

Wikipedia → Image: Wikimedia Commons · NASA/JPL-Caltech · Public domain